Dipper-tooth.



C. B: ANDREWS.

DIPPER TOOTH. APPLICATION FILED APR. 27, 19141.

Patented July 24, 1917.

CHARLES B. ANDREWS, OF HIGH BRIDGE, NEW JERSEY, ASSIGNOR T0 TAYLOR- WHARTON IRON AND STEEL COMPANY, OF HIGH BRIDGE, NEW JERSEY, A COR- POEATION OF NEW JERSEY.

niPrEIt-Too'rH.

Specification of Letters Patent.

Patented July ML, TFM'.

Application filed April 27, 1914. Serial no. 884,561.

To all whom it may concern:

Be it known that I, a citizen of the United States, residing at High Bridge, in the county of Hunterdon and State of -New Jersey, have invented the following described Improvements in Dipper-Teeth.

The invention is an improved reversible point for the teeth of steam shovel dippers and other excavating apparatus, the object contained in such points that is to be worn away in useful service and diminish the proportion required'for attaching the point to its base or support.

The drawings illustrate the preferred form of the invention,

Figure point and base with a part of the base broken away;

Fig. 2 a section of Fig. 1, on line II-II;

Fig. 3 a perspective view ofthe point alone; I

. Fig- 4 a perspective view of the end of the base for such point.

In these figures the body or base of the tooth is indicated at 1, and may be integral with the lip 2 of a steam shovel dipper or connected to it or to any other excavating apparatus in any suitable way. The point fitting on the forward end of the base is. symmetrically formed and reversible so that when worn ofl on its lower side it can be removed and reattached to the base with the other side down, the effective sharpness being thus preserved, and by occasional reversal of the point, the apex or cutting edge thereof can be preserved in substantial coincidence with the axis wb of the tooth, so that the cutting edge will always be maintained at a desired angle with reference to the dipper. The means on the point which form the joint between it and the base, are symmetrically disposed thereon with respect to the said axis a-b, but the means on the base, which are complementary to the point, are unsymmetrical to said axis and so arranged that the seating of the point thereon must take place in a direction which is inclined to the said axis, as will later appear.

The joint-forming means comprise a vertical slot formed between two similar nose portions 3, which project integrally from the end of the base, and are each tapered or pointed with an angle which is determined GHAnLns B. ANoREws,

to increase the proportion of metal.

1 being aside elevation of a tooth by the conditions of use. It is known in the operation of steam shovels that the points of the teeth tend to wear away (on their lower sides) in a plane or surface which lies 7 at substantially the same angle to the axis of equal approximately twice the angle which the wearing surface takes tothe axis of the point as a whole.

On their proximate faces the two tapered nose portions 3 are provided with two sets of mortise grooves marked at and 5,'respectively, and these grooves are both substantially parallel to the line cd and the lower faces of the nose portions.

The point is comprised of two divergent arm or wing portions 6, cast or otherwise formed integrally with a web 7, which ties the wings together. The exterior faces of the portions 6 may be at any desired angle and are desirably symmetrical with the axis a-b when the point is new. The in terior faces are symmetrical with reference to the said axis, and the angle between them is the angle of the nose portions 4 upon which they are adapted to fit and thrust. The web 7 enters and fits the slot between nose portions and for this purpose is provided with integral lugs marked 8, 9, 10 and 11, respectively, there being one lug or set of lugs on each side of the web and symmetrically disposed thereon. These logs constitute tenon members for the mortise groove formation of the base, and by reason of their symmetrical arrangement are adapted to engage and fit the base, irrespective of be entered into the mortise seen that each of the lugs shown, together with one of two others, may form a tenon member to cooperate with one ofthe mortise grooves in the base, and it will be evident that it is not of consequence how many shown four and find that number to be satisfactory. The lug 9, it will be noted, engages. the same mortise groove 5, in both positions of the point, in one case its side 9 being engaged with the bottom of the mortise groove, and in the other case its side 9 being engaged with the bottom of the same groove. The shape of the lug and particularly of the sides 9 and 9 is such as to provide a proper bearing. upon the Wall of its groove in"both positions of reversal. In the present case the grooves are squared at their bottoms and rounded at their tops, and the tenon lug9," as well as the others, is correspondingly shaped, each having two flat faces and two rounded faces. In both positions the point is fitted on the base by sliding the lugs into the mortise grooves, until the wings 6 of the point seat on the nose portions 3; whereupon a fastening bolt 12 is passed through the parts to lock the point in place. The thrust of the point on the base is withstood principally by the bearing of the wing portions 6 upon the nose portions 3, thespreading of the wings being prevented by.the web, and shearing strains on the bolt beilig prevented by the interlocking mortise connection, as well as by the wings, since the principal thrust is in the direction of the line of wear. The metal of the point, reversed from time to time, wears away parallel with the inner faces of the wing portions 6 and until such portions become so thin, or the cutting edge becomes so obtuse, as to be no longer serviceable. The remaining metal, consisting p'actically of nothing but joint, may then scrafpped with minimum of' loss in the form 0 waste.

It will be observed from description that the principle of my invention involves the application of a reversible mortise and tenon joint to the nose of a tooth base, the direction of the joint approximating the line of wear on the point and being 1n oblique relation to the axis thereof.

I claim:

1. A tooth, of the kind described, comprising a base having an approximately triangular joint portion symmetrical to the the foregoing longitudinal axis, and a point having a com plementary joint portion adapted to fit reversibly upon the oint portion of the base, said oint portlons eing formed with lateral mortise and tenon joints which are disposed to engage in either position of the point and the mortises whereof extend at an angle to the axis and approximately parallel to the line of wear of the point.

. 2. A tooth of the kind described, comprising a base having an approximately triangular, vertically-slotted joint portion symmetrical. to the longitudinal axis, and formed in the faces of its slot with mortises extending at an angle to the axis and substantially parallel with the bottom of the joint portion, and a reversible point having a web to enter said slot and top and bottom wings toembrace the joint portion of the base, said web having a plurality of rows of projections arranged at the same angle to the axis as the mortises in the base. A

3. A tooth of the kind described, comprising a base and a point, said base provided with several parallel mortise grooves in oblique relation to the axis of the point and said point being provided with several tenon members adapted for reversible engagement with the said grooves.

4. A tooth of the kind described, compris--- ing a base having two nose portions with a slot'between them and a plurality of mortise grooves formed in the slot substantially parallel with the lower side of the nose porvtions,'in combination with a reversible point for such base provided with wing portions adapted to fit the nose portions, a web adapted to fit the slot, and sets of tenon projections on opposite sides of. the web, diiferent groups of which are adapted to engage difierent mortise grooves in the base according to the position of the point thereon.

5. A tooth'of the kind described, comprising a base and a point, said base being formed with tapering nose portions separated by a vertical slot and having mortise grooves formed in the sides of said slot in oblique relation to the axis of the point, and said point having wing portions to fit the nose portions and a connecting web portion provided with tenon members capable of reversible engagement with said grooves.

6. In a tooth of the kind described, a base having a nose provided with a vertical slot, and a point having wings connected by a web to enter the said slot, the slot being formed'with mortise grooves in its sides and the web having tenon projections to engage said grooves.

In testimony whereof, I have signed this specification in the presence of two witnesses.

CHARLES B. ANDREWS. 

